CDISC Frequently Asked Questions (FAQ)

General Questions

What is CDISC?

CDISC stands for Clinical Data Interchange Standards Consortium. It's a global, non-profit organization that develops and supports data standards for clinical research and healthcare. Founded in 1997, CDISC creates standards that enable the systematic collection, organization, and analysis of clinical trial data, making it easier to share and compare results across studies, organizations, and regulatory submissions.

Why was CDISC created?

Before CDISC, pharmaceutical companies and research organizations used their own proprietary formats for collecting and storing clinical trial data. This lack of standardization made it difficult and time-consuming to combine data from different sources, prepare regulatory submissions, and conduct meta-analyses. CDISC was established to address these challenges by creating universal standards that the entire industry could adopt.

Who uses CDISC standards?

CDISC standards are used by pharmaceutical companies, biotechnology firms, contract research organizations (CROs), academic medical centers, regulatory agencies (like the FDA and EMA), medical device manufacturers, and data management professionals involved in clinical research. The standards have become the industry norm for regulatory submissions worldwide.

Are CDISC standards mandatory?

While not universally mandatory, CDISC standards are required for certain regulatory submissions. The U.S. Food and Drug Administration (FDA) has required CDISC standards for most new drug applications since 2016. The Pharmaceuticals and Medical Devices Agency (PMDA) in Japan also requires CDISC for new drug applications. Many other regulatory agencies strongly encourage or prefer CDISC-compliant submissions.

CDISC Standards Overview

What are the main CDISC standards?

CDISC has developed several key standards:

• SDTM (Study Data Tabulation Model): A standard for organizing and formatting data for regulatory submissions
• ADaM (Analysis Data Model): A standard for analysis datasets used in statistical analysis
• CDASH (Clinical Data Acquisition Standards Harmonization): A standard for case report form design and data collection
• ODM (Operational Data Model): An XML-based standard for exchanging and archiving clinical trial data
• SEND (Standard for Exchange of Nonclinical Data): A standard for nonclinical study data
• Protocol Representation Model: A standard for representing clinical trial protocols in a machine-readable format

What is SDTM?

The Study Data Tabulation Model (SDTM) is CDISC's foundational standard for organizing clinical trial data for regulatory review. SDTM defines how to structure data into standardized domains (datasets) like Demographics (DM), Adverse Events (AE), Vital Signs (VS), and Laboratory Tests (LB). Each domain has specific variables with standardized names, labels, and controlled terminology, making it easier for reviewers to navigate and understand submission data.

What is ADaM?

The Analysis Data Model (ADaM) provides standards for creating analysis datasets used in statistical analyses and generating tables, listings, and figures for regulatory submissions. ADaM datasets are derived from SDTM data and are specifically structured to support the efficacy and safety analyses outlined in the Statistical Analysis Plan. Common ADaM datasets include ADSL (Subject-Level Analysis Dataset), ADAE (Adverse Events Analysis Dataset), and various disease-specific or endpoint-specific datasets.

What is CDASH?

Clinical Data Acquisition Standards Harmonization (CDASH) is a standard for designing case report forms (CRFs) and collecting data at the point of entry. CDASH defines recommended fields and question text for common data collection scenarios. By standardizing data collection, CDASH makes it easier to map collected data to SDTM and reduces the need for extensive data transformation later in the process.

What is the difference between SDTM and ADaM?

SDTM focuses on organizing raw clinical data in a standardized tabulation format suitable for regulatory review, maintaining data as close to its original collection form as possible. ADaM, on the other hand, is designed specifically for statistical analysis and includes derived variables, analysis flags, and variables needed to reproduce the exact analyses presented in the clinical study report. Think of SDTM as the "what was collected" and ADaM as the "what was analyzed."

Implementation Questions

How difficult is it to implement CDISC standards?

Implementation difficulty varies depending on your organization's current processes, data infrastructure, and experience level. For organizations new to CDISC, there's a learning curve involving understanding the standards, controlled terminology, and implementation guides. However, most organizations find that the long-term benefits—including faster submissions, improved data quality, and easier data integration—outweigh the initial investment. Many tools and services are available to facilitate implementation.

What is controlled terminology in CDISC?

Controlled terminology refers to standardized vocabularies that define permissible values for specific variables in CDISC datasets. For example, the SEX variable should use "M" for male, "F" for female, and "U" for unknown, rather than variations like "Male," "male," or "1." CDISC maintains the CDISC Controlled Terminology (CT), which is published by the National Cancer Institute Enterprise Vocabulary Services (NCI EVS). Using controlled terminology ensures consistency across studies and sponsors.

Do I need special software to create CDISC-compliant datasets?

While you can create CDISC-compliant datasets using standard programming languages like SAS, R, or Python, many specialized software tools can streamline the process. These include data mapping tools, validation software, and electronic data capture (EDC) systems with built-in CDISC compliance features. The choice depends on your budget, technical expertise, and specific needs.

What is a Define.xml file?

Define.xml is a metadata file that accompanies CDISC datasets in regulatory submissions. It describes the structure and content of the datasets, including variable names, labels, data types, controlled terminology, derivation methods, and code lists. Define.xml is based on the CDISC ODM standard and allows reviewers to understand the dataset structure without extensive documentation.

How do I validate CDISC datasets?

Validation involves checking datasets against CDISC conformance rules and business rules. CDISC provides validation rules through the CDISC Conformance Rules, and various validation tools are available commercially and through open-source communities. Common checks include verifying domain structure, variable naming conventions, controlled terminology usage, and cross-dataset relationships. The FDA also provides the Pinnacle 21 Community tool for validation.

Specific Standards Questions

What is SEND and who needs to use it?

The Standard for Exchange of Nonclinical Data (SEND) is specifically designed for nonclinical (preclinical) study data, including toxicology and pharmacology studies. The FDA requires SEND for certain nonclinical study submissions. SEND is based on SDTM principles but includes domains specific to animal studies, such as study design, animal demographics, and findings.

What are CDISC therapeutic area standards?

CDISC has developed therapeutic area user guides (TAUGs) and supplements for specific disease areas like Alzheimer's disease, cardiovascular disease, diabetes, oncology, and virology. These provide guidance on implementing CDISC standards for disease-specific data elements, assessments, and endpoints that aren't covered in the general standards.

What is the Protocol Representation Model?

The Protocol Representation Model is a relatively new CDISC standard that provides a structured, machine-readable way to represent clinical trial protocols. This enables better protocol design, facilitates automation in trial execution and monitoring, and supports digital transformation initiatives in clinical research.

Training and Resources

Where can I learn CDISC standards?

CDISC offers various learning resources including online courses, webinars, and training programs through CDISC Education. The CDISC website provides free access to implementation guides, user guides, and standard documentation. Many universities, professional organizations, and commercial training companies also offer CDISC training programs. Additionally, CDISC hosts annual conferences and regional events.

Does CDISC offer certification?

Yes, CDISC offers a professional certification program called the Certified CDISC Professional (CCP) credential. This certification demonstrates proficiency in CDISC standards and is increasingly valued in the clinical data management field.

What are CDISC implementation guides?

Implementation guides (IGs) are detailed documents that explain how to implement specific CDISC standards. They include domain specifications, variable definitions, examples, and guidance on handling common scenarios. The SDTM Implementation Guide and ADaM Implementation Guide are essential references for anyone working with these standards.

Is CDISC membership required to use the standards?

No, CDISC standards are freely available to everyone, regardless of membership status. However, CDISC membership provides benefits including early access to draft standards, the ability to participate in standard development, networking opportunities, and discounts on training and events.

Regulatory and Compliance

Which regulatory agencies accept or require CDISC?

The U.S. FDA requires CDISC SDTM and ADaM for most new drug applications and has required SEND for nonclinical studies since 2016. Japan's PMDA requires CDISC for new drug applications. The European Medicines Agency (EMA) accepts CDISC submissions and encourages their use. Regulatory agencies in Canada, Australia, China, and many other countries also accept or prefer CDISC-compliant submissions.

What happens if my CDISC datasets have errors?

If datasets submitted to regulatory agencies contain CDISC conformance errors, reviewers may issue information requests or deficiency letters asking for corrections. Significant errors could delay the review process. This is why thorough validation before submission is critical. However, minor issues that don't affect data interpretation may not require resubmission.

How often do CDISC standards change?

CDISC periodically updates its standards to address new requirements, incorporate feedback, and support evolving research needs. Major standards like SDTM and ADaM typically release new versions every few years. CDISC follows a transparent development process with public comment periods. Organizations need to stay informed about updates and plan for implementation of new versions.

Future and Evolution

What is CDISC 360?

CDISC 360 is CDISC's strategic initiative to modernize and integrate its standards using a unified foundational model. This represents a shift toward more automated, interoperable, and digital-ready standards that can better support modern clinical research technologies and regulatory processes.

How is CDISC evolving for digital health and real-world data?

CDISC is actively developing standards and guidance to support digital health technologies, wearable devices, electronic health records (EHRs), and real-world data collection. This includes work on standards for remote monitoring, patient-reported outcomes captured via mobile devices, and integration of data from diverse sources.

Will artificial intelligence impact CDISC standards?

AI and machine learning are increasingly being used in clinical research, and CDISC is working to ensure its standards can support AI-driven processes while maintaining data quality, transparency, and regulatory compliance. This includes developing standards for representing AI/ML algorithms and their outputs in clinical trial data.

This FAQ covers the fundamental aspects of CDISC standards, but the field is constantly evolving. For the most current information, visit the official CDISC website or consult with CDISC-certified professionals in your organization.